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1.
This paper addresses one of the issues in contemporary globalization theory: the extent to which there is 'one best way' in which business can be conducted and organizations managed. It uses Czarniawska's 'travels of ideas' model as an organizing framework to present and understand how the concept of 'quality', so important in contemporary approaches to manufacturing and services, and their management, travelled to, and impinged on, a newly opened vehicle assembly plant in Poland. The extent to which new meanings were mutually created in the process of translation is discussed, using ethnographic reporting and analysis techniques commonly used in diffusion research. Parallels between the process of translation as an idea becomes embedded into a new cultural location and the processes which contemporary research has identified as important to organizational learning are briefly discussed in conclusion.  相似文献   

2.
The developmental neurotoxicity of methylmercury (MeHg) in humans has been described following catastrophic events in Minamata Bay, Japan and in Iraq, and following the exposure to lower doses elsewhere in the world. The most common route of MeHg exposure in humans is through the intake of contaminated food, especially fish. Although the precautions against the ingestion of potentially contaminated food during pregnancy are well recognized, precautions against the ingestion of MeHg during lactation are not so uniformly recognized. However, the continued development of the central nervous system during the early postnatal period serves to prolong the period during which this critical system is susceptible to the toxic insult of MeHg. Because no direct method is available to quantitatively assess the lactational transfer of MeHg to humans, a computer-aided simulation method was developed. An available gestational physiologically based pharmacokinetic model was refined and expanded to include parameters and algorithms specific for the elimination of MeHg in breast milk. The predictions of the completed model were compared with experimental data obtained from rodents, and the model parameters were allometrically scaled to humans. Finally, the model was validated by comparing its predictions against the available clinical data for MeHg distribution and elimination in mothers and their nursing infants. This model incorporated current and previous maternal exposures to MeHg to accurately predict the kinetics of MeHg excretion in breast milk and the daily intake by the nursing infant. This model may be used to quantify MeHg intake by the nursing infant, under different rates of maternal MeHg ingestion.  相似文献   

3.
The skin is a route of exposure that needs to be considered when conducting a risk assessment. It is necessary to identify the potential for dermal penetration by a chemical as well as to determine the overall importance of the dermal route of exposure as compared with inhalation or oral routes of exposure. The physical state of the chemical, vapor or liquid, the concentration, neat or dilute, and the vehicle, lipid or aqueous, is also important. Dermal risk is related to the product of the amounts of penetration and toxicity. Toxicity involves local effects on the skin itself and the potential for systemic effects. Dermal penetration is described in large part by the permeability constant. When permeability constants are not known, partition coefficients can be used to estimate a chemical's potential to permeate the skin. With these concepts in mind, a tiered approach is proposed for dermal risk assessment. A key first step is the determination of a skin-to-air or skin-to-medium partition coefficient to estimate a potential for dermal absorption. Building a physiologically-based pharmacokinetic (PBPK) model is another step in the tiered approach and is useful prior to classical in vivo toxicity tests. A PBPK model can be used to determine a permeability constant for a chemical as well as to show the distribution of the chemical systemically. A detailed understanding of species differences in the structure and function of the skin and how they relate to differences in penetration rates is necessary in order to extrapolate animal data from PBPK models to the human. A study is in progress to examine anatomical differences for four species.  相似文献   

4.
当前我国医院间存在严重的"信息孤岛",医院参与医疗信息共享意愿不高,患者的诊疗信息被静态碎片化储存而无法充分有效地利用。考虑到医院进行医疗信息共享将降低患者转移成本,本文构建一个多阶段双寡头动态博弈模型研究医疗信息共享对医院竞争过程中患者转移数量和服务质量水平决策的影响。首先,根据是否存在转移成本,将患者分为新患者和经验性患者,借助Hotelling模型刻画患者的效用函数,分析患者就诊决策。然后,在政府价格规制和不考虑医院利他性情景下,构建了医院累积期望收益目标函数,使用动态规划方法,求解实现医院累积期望收益最大化的服务质量水平,获得了实现患者相互转移且医院在市场中共存的马尔可夫完美均衡。最后,根据医院参与医疗信息共享后患者转移成本降为零,分析与比较信息共享前后患者转移数量和服务质量水平变化。研究发现:在不同医院间本身存在患者转移背景下,医院参与信息共享后,患者转移数量增加但存在一个上限,增加的转移量与患者在医院间的转移成本呈正相关,与初始感知效用的差值范围呈负相关;医院参与信息共享后,均衡状态下的医院服务质量水平高于信息共享前的服务质量水平。因此,在不改变当前医保支付方式下,要加快推进医疗信息共享,政府部门可以根据医院的患者数量和服务质量水平变化对其进行定期补贴,以激励医院积极参与医疗信息共享,本文给出了这个补贴的量化表达。  相似文献   

5.
Increased contamination of the environment by toxic chemicals has resulted in the need for sensitive assays to be used in risk assessment of polluted sites. Traditional tests are useful to detect and measure concentrations of chemicals in the environment and in tissues. However, physicochemical assays possess deficiencies that impair their use in evaluating complex environmental contamination. We have developed cytogenetic procedures, including chromosomal, micronucleus, and flow cytometric assays, to assess the mutagenic damage of petrochemicals and low-level radioactivity on indigenous terrestrial and aquatic wildlife populations. These procedures are sensitive to the perturbation of DNA that results from exposure to mutagenic contaminants in both field and laboratory studies. The use of natural populations of animals in biomonitoring, combined with traditional chemical assays, will ultimately provide sufficient information to estimate the risk to human health and environmental quality from anthropogenic pollution.  相似文献   

6.
The persistent gap in flood risk awareness in Canada, and elsewhere in North America, is a continual source of worry for researchers and emergency managers; many people living in at‐risk places are simply unaware of risks and of their proximity to hazards. This study seeks to understand which residents were aware of flood risk, using unique representative survey data of Calgary residents living in the city's flood‐prone neighborhoods collected after the devastating and costly 2013 Southern Alberta Flood. The article uses logistic regression models to analyze which residents were aware of risk to their homes. Findings indicate that, in addition to various demographic predictors, many of the geographic predictors (including the elevation of one's home relative to the river) are significant predictors of awareness. Having a direct sight line to one of Calgary's two rivers is also a significant predictor in some of the models, suggesting that the visibility of hazards matters for flood risk perception, although this effect fades when many of the geographic predictors are added. Finally, the models indicate that several variables related to local, neighborhood‐based social networks are significant as well. These findings reveal that both physical surroundings and social context are important for understanding risk awareness. The article concludes by discussing the relevance for social science research on disasters and hazards, as well as for planners and emergency managers.  相似文献   

7.
This paper investigates the awareness, use and effectiveness of improvement initiatives in organisations of different sizes and in different countries. In particular, comparisons are made between large firms and small and medium enterprises (SMEs), between organisations in the developing and developed worlds and between organisations in China and India and the rest of the developing world. A questionnaire survey of 453 organisations across 44 countries was conducted with the findings indicating that there are significant differences in comparability of tools. For some tools there are no significant differences between developed and developing countries as well as between large organisations and small organisations. For other tools, there are significant differences with organisations in developing countries, in general, more aware and more likely to use business improvement initiatives when compared to organisations in developed countries. Similarly, organisations in China and India have a higher awareness of and are more likely to adopt improvement initiatives when compared to the rest of the developing world. Finally, larger firms are more aware and more likely to use improvement initiatives when compared to SMEs.  相似文献   

8.
Penny Dick 《Work and stress》2000,14(3):226-244
The police profession is one in which acute stressors are encountered more frequently than in other occupations. Using the personal accounts of 35 police officers attending an in-house stress counselling clinic, the aim of the present study was to provide a qualitative examination of how the institutional context of policing influenced the ways in which acute stressors signified to individual police officers experiencing felt distress. Using the framework of Rational Emotive Behaviour Therapy as an analytical tool, it is argued that beliefs contributing to the experience of felt distress are related to the way in which policing as both an identity and an activity is constructed through the police organizational culture. Not only do these constructions influence the ways in which officers perceive themselves and their environments, but they also operate at the collective level to 'normalize' some emotional responses and to 'pathologize' others which, it is argued, could impact upon the outcomes of interventions such as stress counselling.  相似文献   

9.
顾客忠诚度是网络商家维护市场地位、保持持续竞争优势的重要因素。然而,网络环境下顾客忠诚度的复杂性和不确定性却成为阻碍电子商务进一步发展的瓶颈。因此,本文通过对以往文献的梳理,构建了以信任、在线网站特性、线下物流服务质量、顾客满意度、转换成本为外因潜在变量,以顾客忠诚度为内因潜在变量的假设模型,并以问卷调研的方式收集实证数据,采用因子分析和结构方程模型揭示网络环境下顾客忠诚度的影响因素和作用机制。研究发现:在网络环境下,信任不仅可以通过影响顾客满意度来间接地影响顾客忠诚度,而且可以成为顾客忠诚度的直接前因变量;在线网站特性和线下物流服务质量共同作用于顾客满意度的提升,并间接地影响顾客忠诚度的积累;顾客满意度和转换成本是网络环境下顾客忠诚度的主要影响因素。研究结论较为全面地反映了网络环境下顾客忠诚度的影响因素和作用机制,对于网络零售商有针对性地实施顾客忠诚计划有着十分重要的参考价值。  相似文献   

10.
There is increasing interest in being able to express the consequences of exposure to potentially toxic compounds in monetary terms in order to evaluate potential cost-benefit relationships of controlling exposure. Behavioral effects of acute toluene exposure could be subjected to cost-benefit analysis if the effects of toluene were quantitatively compared to those of ethanol ingestion, which has been monetized for applied contexts. Behavioral effects of toluene and ethanol were quantified by meta-analysis of studies from the peer-reviewed literature describing their effects on choice reaction time (reaction time in a test requiring a subject to choose among two or more alternatives before responding). The internal doses of these compounds were estimated by a general physiological and toxicokinetic (GPAT) simulation from exposure parameters provided in the reports. The reported effects were converted to a common metric (proportion of baseline) and related to the estimated internal doses of toluene and ethanol, from which dose-effect equations were fitted. The estimated effect of toluene was compared to the estimated effect of ethanol on the same dependent variable by deriving a dose-equivalence equation (DEE) to express the dose of toluene as an equivalent dose of ethanol on the basis of equal effect magnitude. A nomogram was constructed by GPAT simulation to relate the environmental exposure concentration of toluene to the equivalent effect magnitude of a range of ethanol internal doses. Behavioral effects and their evaluation are determined by internal doses, which in turn are determined by a variety of variables. In addition to concentration and duration of exposure, which determine internal dose by pharmacokinetic processes, the activity level of exposed persons is a major factor. This analysis provides a continuous function of the consequences of toluene exposure expressed as ethanol-equivalent doses within confidence limits. The resulting function has the potential to estimate the monetary values of behavioral deficits caused by a range of exposures to toluene from existing monetized information on ethanol.  相似文献   

11.
With the intensifying global efforts to eradicate wild polioviruses, policymakers face complex decisions related to achieving eradication and managing posteradication risks. These decisions and the expanding use of inactivated poliovirus vaccine (IPV) trigger renewed interest in poliovirus immunity, particularly the role of mucosal immunity in the transmission of polioviruses. Sustained high population immunity to poliovirus transmission represents a key prerequisite to eradication, but poliovirus immunity and transmission remain poorly understood despite decades of studies. In April 2010, the U.S. Centers for Disease Control and Prevention convened an international group of experts on poliovirus immunology and virology to review the literature relevant for modeling poliovirus transmission, develop a consensus about related uncertainties, and identify research needs. This article synthesizes the quantitative assessments and research needs identified during the process. Limitations in the evidence from oral poliovirus vaccine (OPV) challenge studies and other relevant data led to differences in expert assessments, indicating the need for additional data, particularly in several priority areas for research: (1) the ability of IPV‐induced immunity to prevent or reduce excretion and affect transmission, (2) the impact of waning immunity on the probability and extent of poliovirus excretion, (3) the relationship between the concentration of poliovirus excreted and infectiousness to others in different settings, and (4) the relative role of fecal‐oral versus oropharyngeal transmission. This assessment of current knowledge supports the immediate conduct of additional studies to address the gaps.  相似文献   

12.
亚洲金融危机和希腊债务危机表明中小国家也可以引发严重危机,这种现象不容忽视。基于复杂网络理论,使用2007年国际贸易数据构建了包含148个国家和地区的全球宏观经济网络;利用S.I.R模型模拟了各国在发生不同等级的金融危机时所影响到的国家数量和经济总量,发现不同国家传染力的差异存在一定的区域特征,许多经济总量不大的国家也具有引发严重危机的潜力;使用动态聚类法对各国的传染力进行分类,处于类别1至类别4的国家为国际金融危机潜在传染源;通过计算传染力与GDP、进口和网络拓扑结构指标的Spearman相关系数发现,GDP、进口较大以及聚类系数小的国家在低危机等级时就表现出一定的负面溢出;而贸易伙伴较多以及处于网络中心位置的国家在较高的危机等级下具备引发严重危机的潜力;使用2009年的数据进行模拟,本文的主要结论依然稳健。  相似文献   

13.
The Group Technology theory identifies and groups similar parts into families and machines into cells, advantages being in the similarity of the parts made in each cell, and designing and manufacturing. The benefits are: simple material flow, cost reduction in material handling, reduction in work in progress, reduction in the cycle time and set-up time, increased manufacturing flexibility, increased quality, and increased job satisfaction. The objective of the work presented in this paper was to develop a Group Technology (GT) algorithm by means of cell analysis for the design of the productive system to batch production, e.g. water heater manufacturing, system manufacturing, lathes manufacturing, etc. The TGIP algorithm allows the definition of technical and economical parameters for the application of Group Technology, also taking into account the demand for the performance of the algoof heating gasrithm. The benefits of the algorithm developed are the focus on solving the case of multiple machines and the assignment of the parts to the groups related to the load of the machines; also it allows the definition of technical and economical parameters to differentiate the machines that do the same operation or even the consideration of the demand for a certain period of time.  相似文献   

14.
The Evolution of Knowledge and the Dynamics of an Industry Network   总被引:1,自引:0,他引:1  
The paper moves a step forward in the direction of establishing a connection between the structure and evolution of knowledge bases and the structure and evolution of organizational forms in innovative activities in a science-intensive industry. The paper has an explicit focus on the dynamics of the network of collaborative agreements in R&D in the pharma/biotech industry after the “molecular biology revolution”. Using a comprehensive dataset, built by the authors integrating several sources in the industry, the dynamics of the network over time is extensively analyzed. With regards to network structure, it is found that, while the size of the network increases over time due to net flows of entry, its topological properties remain relatively unchanged. The evolution of the network has occurred without relevant deformations in the core-periphery profile. With regards to age-dependent propensity to collaborate, the paper finds that the extent of inter-generational collaboration is much more significant than intra-generational collaboration. In addition, the propensity of firms of a given generation to enter into collaboration with firms of a different generation increases with the distance between the two, while the total number of intra-generational collaborations decreases over time and, moreover, tends to decrease for most recent generations. In the paper a unitary and coherent explanation of the evidence is developed, coming to reveal the existence of a striking isomorphism between structural properties of the dynamics of knowledge and of the evolution of network structure. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

15.
The aim of this article is to build a methodology allowing the study and the comparison of the potential spread of BSE at the scale of countries under different routine slaughtering conditions in order to evaluate the risk of nonextinction due to this slaughtering. We first model the evolution in discrete time of the proportion of animals in the latent period and that of infectives, assuming a very large branching population not necessarily constant in size, two age classes, less than 1-year-old animals, and adult animals. We analytically derive a bifurcation parameter rho(0) allowing us to predict either endemicity or extinction of the disease, which has the meaning of an epidemiological reproductive rate. We show that the classical reproductive number R(0) cannot be used for prediction if the size of the population, when healthy, does not remain stable throughout time. We illustrate the qualitative results by means of simulations with either the British routine slaughtering probabilities or the French ones, the other conditions being assumed identical in both countries. We show that the French probabilities lead to a higher risk of spread of the disease than the British ones, this result being mainly due to a smaller value of the routine slaughtering probability of the adult animals in France than in Great Britain.  相似文献   

16.
ABSTRACT

Feedback is often used in Organizational Behavior Management to improve employee performance. Accurate feedback results in greater improvements in performance and accurate observations enable accurate feedback. However, employees may find providing feedback to peers aversive. The present study contrived a method to evaluate whether instructing individuals to deliver feedback following observations impacted the accuracy of those observations. Five college-aged participants were exposed to a counterbalanced ABAB design. In the observation-only condition (Condition A) participants conducted observations of confederate posture, scoring whether the confederate’s feet and back were “safe” or “at risk.” In the required-feedback condition (Condition B) participants observed and collected data identically to phase A, but were additionally instructed to deliver feedback regarding confederate postures following each session. The results show that all five participants demonstrated higher accuracy of observations in the observation-only condition. Factors potentially influencing lower accuracy when feedback was required are discussed.  相似文献   

17.
Dermal absorption experiments form an important component in the assessment of risk from exposure to pesticides and other substances. Much dermal absorption data is gathered in rat experiments carried out using a certain standard protocol. Uncertainties in these data arise from many sources and can be quite large. For example, measurements of the systemic absorption of hexaconazole differed by more than an order of magnitude within a single experiment. Two diniconazole studies produced quite different results, due to minor differences in protocol and in chemical formulation. Limits of detection can also prevent accurate measurement when the amounts absorbed are small. These examples illustrate the need for measuring and reporting uncertainties in estimates that are based on these data. The most direct way to estimate uncertainty is to compute the sample standard deviations of replicate measurements. By pooling these estimates across dose and duration groups for which they are similar, the number of degrees of freedom is increased, and more precise confidence intervals can be obtained. In particular, the ratio of upper to lower 95% confidence limits was reduced by as much as ten-fold for hexaconazole, seven-fold for uniconazole, and nearly four-fold for propiconazole.  相似文献   

18.
Models of Neurotoxicity: Extrapolation of Benchmark Doses in Vitro   总被引:4,自引:0,他引:4  
In risk assessment, no observed exposure level (NOAEL) and benchmark dose (BMD) are usually derived either from epidemiological studies in humans or from animal experiments. In many in vitro studies, concentration-effect/response curves have been analyzed using different mathematical models finalized to the identification of EC50. In the present article, we propose a model to fit dose-response curves in vitro. The BMD approach has been used to compare the cell viability (MIT assay) of different rat (C6 and PC12, glial and neuronal, respectively) and human cell lines (D384 and SK-N-MC, glial and neuronal, respectively) after 24-hour exposure to the following neurotoxic substances: manganese chloride (MnCl2), methyl-mercury (Me-Hg), and the enantiomers of styrene oxide (SO). For all rat and human cell lines, the potency of the examined compounds was: MnCl2 < S-SO < R-SO < Me-Hg. A preliminary comparison with in vivo toxicity data for these substances gave rise to consistent results. Whereas a reasonable agreement between in vitro and in vivo data has been found for Mn and styrene oxide, a wide scatter of LOAEL has been reported for Me-Hg and these appear to be either much higher or lower than the BMD for the MIT assay we observed in vitro.  相似文献   

19.
Much has been written about the development and application of quantitative methods for estimating under uncertainty the long-term radiological performance of underground disposal of radioactive wastes. Until recently, interest has been focused almost entirely on the technical challenges regardless of the role of the organization responsible for these analyses. Now the dialogue between regulators, the repository developer or operator, and other interested parties in the decision-making process receives increasing attention, especially in view of some current difficulties in obtaining approvals to construct or operate deep facilities for intermediate or high-level wastes. Consequently, it is timely to consider the options for regulators' review and evaluation of safety submissions, at the various stages in the site selection to repository closure process, and to consider, especially, the role for performance assessment (PA) within the programs of a regulator both before and after delivery of such a submission. The origins and broad character of present regulations in the European Union (EU) and in the OECD countries are outlined and some regulatory PA reviewed. The issues raised are discussed, especially in regard to the interpretation of regulations, the dangers from the desire for simplicity in argument, the use of regulatory PA to review and challenge the PA in the safety case, and the effects of the relationship between proponent and regulator. Finally, a very limited analysis of the role of PA in public hearings is outlined and recommendations are made, together with proposals for improving the mechanisms for international collaboration on technical issues of regulatory concern.Until August 13, 1997, the author was employed as a Principal Pollution Inspector by the Environment Agency (EA) of England and Wales. Responsible for managing the development and application of the regulatory postclosure assessment capability of Her Majesty's Inspectorate of Pollution (HMIP) between 1982 and 1996, when HMIP was merged with the National Rivers Authority and the Waste Regulatory Authorities to form the EA on April 1, 1996. Represented HMIP/EA on a number of international committees related particularly to PA; 20 Bonser Road, Twickenham, Middlesex TW1 4RG, U.K.  相似文献   

20.
One of the lay public's concerns about genetically modified (GM) organisms (GMO) and related emerging technologies is that not all the important risks are evaluated or even identified yet--and that ignorance of the unanticipated risks could lead to severe environmental or public health consequences. To some degree, even the scientists who participated in the analysis of the risks from GMOs (arguably the people most qualified to critique these analyses) share some of this concern. To formally explore the uncertainty in the risk assessment of a GM crop, we conducted detailed interviews of seven leading experts on GM oilseed crops to obtain qualitative and quantitative information on their understanding of the uncertainties associated with the risks to agriculture from GM oilseed crops (canola or rapeseed). The results of these elicitations revealed three issues of potential concern that are currently left outside the scope of risk assessments. These are (1) the potential loss of the agronomic and environmental benefits of glyphosate (a herbicide widely used in no-till agriculture) due to the combined problems of glyphosate-tolerant canola and wheat volunteer plants, (2) the growing problem of seed lot contamination, and (3) the potential market impacts. The elicitations also identified two areas where knowledge is insufficient. These are: the occurrence of hybridization between canola and wild relatives and the ability of the hybrids to perpetuate themselves in nature, and the fate of the herbicide-tolerance genes in soil and their interaction with soil microfauna and -flora. The methodological contribution of this work is a formal approach to analyzing the uncertainty surrounding complex problems.  相似文献   

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